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Strict Standards: getdate(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/New_York' for 'EST/-5.0/no DST' instead in /homepages/18/d163655616/htdocs/forum/index.php on line 86[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3824: Cannot modify header information - headers already sent by (output started at /index.php:86)[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3826: Cannot modify header information - headers already sent by (output started at /index.php:86)[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3827: Cannot modify header information - headers already sent by (output started at /index.php:86)[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3828: Cannot modify header information - headers already sent by (output started at /index.php:86)SKY-MAP.ORG / WIKISKY • Index page

Black Holes
A black hole is defined to be a region of space-time where escape to the outside universe is impossible. The outer boundary of this region is called the event horizon. Nothing can move from inside the event horizon to the outside, even briefly, due to the extreme gravitational field existing within the region.

Big Bang
In physical cosmology, the Big Bang is the scientific theory that the universe emerged from a tremendously dense and hot state about 13.7 billion years ago. The theory is based on the observations indicating the expansion of space (in accord with the Robertson-Walker model of general relativity) as indicated by the Hubble redshift of distant galaxies taken together with the cosmological principle.

Extraterrestrial Life
Extraterrestrial life is life that exists and originates outside the planet Earth, the only place in the universe currently known by humans to support life. Its existence is still hypothetical as there is currently little, if any, evidence of other planets that can support life, or actual extraterrestrial life that has been widely accepted by the scientific community.